This invention relates generally to the field of discharge lighting. In particular, it relates to discharge lighting with a unique channel configuration which, for reasons to be described herein, produces lamps which operate at high efficiency. They are particularly efficacious for the automotive and downlighting markets, to name just two.
Generally, there are two distinct types of lighting requirements, those in which direction of the light is relatively unimportant, and those in which the light must be directed in a particular manner subsequent to its generation. The present invention, while suitable for either application, is particularly well suited for the latter.
An example of the latter category is automotive lighting. After light is generated by the lamp, it must be focused/dispersed according to somewhat exacting standards. While the requirements for headlight sidemarkers, tail lights, brake lights, directionals, hazards, CHMSLs (center high-mounted stop lights), etc. are all different--they share the characteristic of needing to be directed in some specific manner.
Typically, these lights are constructed of a lamp element (for generating light) and a lens element (for directing the light). Lamp elements generally fall in to three categories: HID, incandescent, and discharge. Discharge lamps are generally characterized as having a sealed envelope filled with a gas which contains atoms/ions which emit light when excited.
Commonly assigned patent application Ser. No. 60/042,568 is directed to a discharge lamp formed by a plurality of glass layers with channels formed therebetween, the entirety of which is incorporated herein by reference. It teaches the desirability of forming a secondary gas-containing channel to act as a reservoir to replenish the gas in the primary channel (the discharge channel). That innovation allows for the lamp to operate at low pressure which is desirable for high light output while solving the long-known, life-reducing problem of sputtering.
Although that design is a tremendous improvement over the previous state of the art, it is not perfect. There exists a need to provide a lamp which possesses longer life with no trapped air.
As mentioned above, there has been recent interest in the use of neon discharge lamps for automotive use. Plaguing this application are problems of light focus, power requirements, and lamp life.